1. Field of the Invention
The present invention relates to a common-channel message conversion method for a communication network interface between exchange systems, and in particular to an improved common-channel message conversion method for a communication network interface between exchange systems which makes it possible to convert a consultative committee international telegraph and telephone (CCITT) common-channel message format and an American national standards institute (ANSI) common-channel format of a signal message processor of a third signal message transmission level among hierarchical structures of a common-channel signal method so that a common-channel signal method can be interfaced between a digital communication network (DCN) which is implemented by the CCITT method and an advanced mobile phone service (AMPS) which is one of the analog communication network which is implemented by the ANSI signal method, for thus interfacing the DCN network and the AMPS network by using one exchange system.
2. Description of the Conventional Art
FIG. 1 is a diagram of a conventional common-channel signal message processor.
As shown therein, the conventional common-channel signal message processor includes a mobile application part (MAP) 10 which is connected for defining a mobile communication protocol which is necessary for a connection between a mobile communication subscriber and a providing service, a transition capabilities applicant part (TCAP) 20 for providing a protocol for transferring an information to a user in accordance with the definition of the MAP 10, a signal connection control part (SCCP) 30 for connecting a service system to a user in accordance with a mobile communication protocol from the TCAP 20, and a signal message transfer part (MTP) 40 for controlling a communication network which is necessary for a service providing of the SCCP 30.
The MTP 40 includes a first level 41 which defines a physical, electrical, and functional characteristic of a signal data link, a second level 42 which defines a procedure and function related to the signal message transfer operation through one signal data link, and a third level 43 having a signal network management unit 43-1 and a signal message processor 43-2, which third level 43 defines a procedure and function related to the message transfer operation between signal network signals.
FIG. 2 is a diagram illustrating a conventional common-channel signal match exchange subsystem.
As shown therein, the common-channel signal match exchange subsystem (an Access Switching Subsystem: ASS-7) for generating a common-channel signal message flow includes a signalling message handling part (SMHP, #0 through #15) 50 for processing and managing the signal message in cooperation with the definition of a procedure and function related to the message transfer operation between network signals, a common-channel signal terminal group (STG, #0 through #3) 60 for processing a signal message in accordance with a procedure and function related to the signal message transfer operation through the signal data link connected to the SMHP 50 by a U-link, and a signal terminal (ST, #0 through #31) (not shown) separately connected to each of the STG 60 (#0 through #3).
The SMHP 50 (#0 through #15) is connected between an ASS-7 inter processor communication unit ASS-7 IPCU and a signal terminal network IPCU STN IPCU, and a processor communication control board assembly (PCCA) 51 for controlling the communication between processors, a main processor and memory management board assembly (MPMA) 52, and a signal bus interface board assembly (SBIA) 53 are connected to the main processor system bus (MPS-BUS). In addition, the STG 60 (#0 through #3) is connected to the STN IPCU by the U-link, and is connected to a signal terminal management logic board assembly (SMLA) 61 for managing the signal terminal, a signal terminal management processor assembly (SMPA) 62, the SMLA, and the SMPA by the signal data link. A signal terminal control board assembly (STCA, #0 through #31) for controlling the signal terminal is further connected.
The construction of the system is the same as the hierarchical structure of the common-channel signal message of the DCN network and the AMPS network.
However, when comparing the routing label which is a parameter indicating the comprehensive name of each device of the DCN network and AMPS network, as shown in FIG. 3, the routing label of the local system based and CCITT based signal method is formed as follows: a signal link selection (SLS) "A" of four bits, a message originating point code (OPC) "B" of 14 bits, and a message destination point code (DPC) "C" of 14 bits are formed in four bytes. In addition, as shown in FIG. 4, a signal link selection code (SLS) "A" of 5 bits, an OPC "B'" of 24 bits, a DPC "C'" of 24 bits, and an auxiliary bit "D" of 3 bits are formed in a routing label of the ANSI method and 7 bytes.
The DPC denotes a signal point code where a subscriber generated a message is positioned, and the OPC denotes an exchange signal point for finally processing the message. Here, there is a difference of the number of bits of the local system based and CCITT and ANSI signal method due to a difference of the number of the signal points.
In addition, the subsystem used in the DCN network and AMPS network will now be explained. For the DCN network, a plurality of subsystems, namely, the MAP is classified into a subscriber position register and a visitor position register, and for the AMPS network, one subsystem of the MAP is used.
The hierarchical structure of the DCN network and the AMPS network is the same; however, since the operation and data value are different, it is impossible to directly perform the interface therebetween.